Carburetor with lagging bypass air valve
US5299548A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 18, 1992 |
| Grant date | Apr 5, 1994 |
| Priority date | — |
| Expiry date | Dec 18, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An improved carburetor useful for reducing emissions of small gasoline powered engines commonly used to power lawnmowers and the like has a bypass air inlet and valve for venting amounts of fresh air into the fuel/air mixture to lean the mixture prior to combustion. The enleanment of the fuel/air mixture reduces carbon monoxide and hydrocarbon emissions. The valve lags the engine load condition such that during a sudden high load condition (e.g. during acceleration) the valve remains momentarily closed to provide a rich fuel/air mixture. Likewise, during a sudden lightened load condition (e.g. during deceleration or shutoff) the valve remains momentarily open to provide a lean fuel/air mixture. Hence, emissions are reduced while engine performance and response are not compromised. In the preferred embodiment, a mechanical linkage connects the bypass air valve to the engine throttle. The lagging function is controlled by a mechanical or electrical damper. In an alternate embodiment, the lagging bypass valve is controlled according to engine temperature which inherently lags the current engine load condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.